Falling through the Floor

In Angel of Darkness, it can happen, that fall through the floor or wall and end up in the next level. (By the movable rubble in Bouchards Hideout, on the bridge in Archeaological Dig, all sloped walls in Aquatic Research Facility...)

There are also reports, that you just keep falling. (Cafe Metro, Outside the Louvre)

It seems that sometimes, floors, walls and other surfaces are not properly connected.